In an effort to find the perfect cycling slipper, I’ve tested a few recently and figured I’d share the experience. Of course, shoes are highly subjective to the foot occupying them so I’ll try to keep an empirical tone.

Bont vs Giro vs Spiuk

Tested from left to right are:

Bont Vaypor+ – Expensive counter-culture shoe.

Giro Prolight SLX – Simple and lightweight shoe from last season, found at closeout.

Spiuk ZS15RC – Euro shoe from the small Spanish brand

Bont Vaypor+

The expensive heat moldable shoe boasts enlightened fit that Bont claims was inspired by the human foot, rather than a traditional shoe. I followed the guide and baked the shoes in my oven then loitered in the kitchen with the hot cycling shoes for while. I’m not convinced the molding process improved the fit drastically, but it probably didn’t hurt especially since no one witnessed the event; saving what little integrity I hope I still have left.

Weight: The Vaypor+ is a light shoe. It’s a fan favorite on the top French cycling forum Velo Optimal in an 89 page thread dedicated to the pursuit of finding the perfect lightweight road bike shoe. Here’s my size 42.5 Vaypor+ all fitted with Speedplay cleats (subtract 60 grams and you’ll have the weight of the shoe only ~ 277g)

Bont Vaypor+ with Speedplay Cleats

General Fit: The Vaypor+ has a very large toe-box. My toes have more than enough room to curl up, move about, take a stroll, or go on vacation should one toe get sick of hanging out the others all the time. For me, that’s just too much wiggle room as the tops of my toes would sometimes get irritated from rubbing the top of the toe-box as they migrated around. Of course, this is a big advantage for people who need extra real-estate in their shoes.

Adjusting the Fit: The Atop dials that came with my Bonts are an older version (I received these shoes in July 2013) and can only be micro-tightened, but to loosen, the dial simply releases the tension fully. Therefore, if you tighten one notch too much, you have to release and start all over. Apparently Atop has a newer version that mimics the Boa dial so micro adjusting can be done for both tightening and loosing the wire lace system. However, as of summer 2014, it appears that the Vaypor+ is being shipped with Boa dials which are fully micro-adjustable in both directions. Guess I missed out on that one.

Bont Vaypor+ with Atop dials

Longevity: Granted I didn’t ride a lot between August of 2013 and June of this year, but the Vaypor+ is holding up quite well. There is hardly any indication of wear as the toe bumper and heel cup are sturdy and rugged.

Insole: The Vaypor+ comes with a very thin insole which didn’t work with my foot profile. I’ve constantly been trying insoles from other shoes trying to find the best fit for me.

Bont Vaypor+, stiffest sole in the shootout

Riding notes: The first thing I noticed about the Bonts compared to my previous Sidi shoes was how hot they were. Despite the toe box having small perforations, there is little air exchange inside the shoe when riding. This is likely due to the 100% use of leather for the upper, rather than a mix of synthetic mesh and leather that other shoes incorporate. I do not have over-heated feet so this was more of an initial observation rather than a deal-breaking issue but on very hot days a little ventilation would be nice. On cold days, this cozy shoe is a great choice. The carbon sole is perfectly stiff and the stack height is so low that I had to move my saddle down quite a bit. It’s been said that the closer your foot is to the spindle, the more power is translated into the pedal stroke, so this is a good thing.

Personal Verdict: It’s a great shoe but I’m still trying to find the perfect insole as I’m still getting hot-spots after 3 hours. In addition to the large toe-box, the wire lace system seems to pinch the upper edges of my foot and aggravates the the tibialis anterior tendon which results in visually red and slightly painful areas once the ride is done and the shoes come off. The Bont, more than any shoe, tends to tighten laterally first, and vertically second. This can be troublesome for riders with flat feet like myself who need the vertical clamping component. It should be noted, however, that besides my personal fit issues, it does have a great sole, low profile, durable structure, and great leather upper. With the addition of Boa dials in 2014 and selecting the right insole (because the standard insole is plain awful, many will pick this above the narrow and fragile S-Works for it’s durability and stiffness or for riders who need a larger toe box.

Giro Prolight SLX

While these shoes originally retailed for $365 (and the 2014 SLX II shoe does sell for this price) I picked up these 2013 model shoes from Giro this year for the bargain price $165.

Giro Prolight SLX on the scale without cleats

Weight: The Prolight SLX is a shocking 199 grams in size 42, which is 78 grams lighter than the very lightweight Bonts. Giro accomplished this by using 3 simple velcro closures, and Easton EC90 carbon sole and a good amount of synthetic mesh on the uppers.

Giro uses Easton’s EC90 Carbon sole

General Fit: The Prolight SLX has what I would consider a more ‘standard’ fit, which is to say they fit more like Sidi shoes. The toe-box is not overly wide like the Bonts and the fit through the midfoot is not overly narrow like the Specialized S-Works. The heal cup may not be as ‘locked in’ as Sidi, but it’s far stiffer than the 2013-2014 Specialized S-Works and doesn’t trail Sidi by much. For me, there isn’t much to say because the shoe basically disappears from my consciousness while pedaling.

Adjusting the Fit: 3 Velcro straps. Easy like kindergarten. The third strap is fairly short so if you typically max out your top shoe strap, you might not be able to use the Prolight SLX. The 2014 version (SLX II) incorporates a slightly longer strap. For the average foot, however, I don’t think this will be an issue.

Longevity: At 199 grams, it would be expected that the shoe is fairly delicate and fragile. It does not feel as robust as the Vaypor+ with it’s tugboat size toe bumper, but it feels much more durable than the S-Works shoe. As most of the upper is synthetic mesh or ‘vernice’ leather, I think it will hold up just fine. The simple velcro straps are also likely to outlive Boa or Atop or other wire lacing systems (even though Boa and Atop should be replaceable).

Insole:

Prolight SLX Insoles (Left: Standard, Right: Adjustable Arch)

The Prolight SLX comes with a very nice standard insole that’s already much better than the Bont. However, Giro decided to step it up and include a second pair that has a deeper heal cup and an adjustable arch system.

Giro Insoles (Standard red, Adjustable black)

Adjustable arches in Small, Medium, and Large

I was eager to ride so I just threw the shoes on my feet with the standard insole and had no problems, but certainly Giro is giving you the ability to fine-tune your shoe so you get the perfect fit. Something Bont and Spiuk did not do. Perhaps one of these extra insoles could be borrowed to breathe new life into the Bonts.

Riding notes: The Prolight SLX is indeed a light shoe. It goes mostly unnoticed during the ride while providing a very stiff platform. The breathability is great and I have not encountered any issues yet. On long 3-5hr rides, I have gotten a few mild hot spots but with the numerous insole configurations, it’s just a matter of getting it dialed in.

Personal Verdict: A great simple shoe that does what it should without being fancy or stand out from the rest. This one is a keeper. At $165 for the white version, and a silly $119 for the black version, these are a great bargain. It doesn’t pretend to be a luxurious super expensive shoe, but it seems to fit better than some shoes that do.

Spiuk ZS15RC

Spiuk is a relatively small cycling company located in the Basque mountains that continually crank out some very nice cycling gear. Currently, they do not sell or market their products in the US, but after a great experience with their helmets and sunglasses while living in Europe, I decided I would give their top-of-the-line road shoe a try, even with slow international shipping. After all, everyone needs a pair of non-white shoes for rainy days or perhaps a shoe that maximizes visibility on the road during the early spring and fall.

Going with the Fluo, the Spiuk ZS15RC

Weight: At 299 grams with Speedplay cleats, and 239 grams for the shoe only in size 42, the ZS15RC is a very light shoe. This came as a bit of a surprise since it bested the Bonts which are renowned for their svelteness, but cost twice as much and use the same Atop dials.

General Fit: The Spiuks have a similar ‘standard’ fit as the Giros. However, they do feel more comfy, perhaps because Spiuk incorporated a little more padding on the inside of the shoe than the minimalist Prolight SLX. The Atop wire lacing system feels good since there is ample padding in the tongue and the heal cup provides good support. Perhaps it’s due to the additional padding, but I felt no areas of tightness or discomfort throughout the shoe.

Spiuk ZS15RC: atop view

Adjusting the Fit: Like the Bonts, Spiuk went with the Atop dials. While these also cannot be micro-adjusted in both directions, I was familiar with the protocol after riding with the Vaypor+ for a year. Perhaps it’s because the shoe is not as wide as the Bont, I found the adjust ability better and more granular than the Vaypor+ which tended to have a very narrow “sweet spot” when it came to tightness. The Spiuk shoe didn’t have the same “laterally tight first, vertically tight second” mantra, but a more predictable overall tightness when the Atop dials were hunkered down. For this reason, I found the ZS15RC much more forgiving and user friendly in regard to fit.

Longevity: The Spiuk shoes utilize a highly perforated vernice upper with reinforced toe bumper and outer heal. My only hesitation is something I would not notice but a few reviews on Wiggle have stated that the top anchor which holds the wire lace to the shoe can rip out. Still, there are very few people who experienced this and the shoe does get great reviews overall. Just something to keep an eye on.

Insole: The Spiuk comes with 2 insoles which I found to be very comfortable. One is dedicated for the summer months and one is dedicated for colder rides. A pretty nice touch!

Cool and Warm Spiuk insoles

Difference between the Cool insole (top) and the Warm insole (bottom)

Sniff Test: A cycling industry first, this shootout also included a sniff test to determine which shoe smells the best. Our judge did not waver about the winner, scoring the Spiuk an incredible 2.7182818 on a scale of 3.1415927:

Sniff Test Winner

Riding notes: The first thing that struck me was how comfortable the shoe is. Going from the Bont to the Spiuk was like the difference between a cheap rental ski boot and a well cushioned running shoe. I’m sure I’m being overly harsh here, but the Spiuk is an incredibly cushy shoe. The sole is not as stiff as the Bont and not as stiff as the Giro’s Easton EC90 sole, but it’s still very capable and only the meanest and angriest sprinters will dismiss the Spiuk in favor for a beefier shoe. The ventilation is also very good. The sole’s stack height is the highest out of the 3 tested. It’s not a big difference going from the Prolight SLX to the Spiuk, but going from the very low Bont to the higher Spiuk on the same bike will probably require a seatpost adjustment (or you can just choose to ignore it to prove how resilient and open-minded you are to changes in your position).

Personal Verdict: The Spiuk ZS15RC is probably the most comfortable out of the 3 tested here. Those who enjoy short 1hr rides with group sprints and intervals that test your 5s maximum wattage might choose a different slipper. My only gripe was the high stack height, but it’s not a huge negative. While I thought these shoes might sacrifice performance for comfort, the rides I’ve done with these shoes always end up being some of the fastest. Maybe it’s the shoe, or maybe it’s just hard to ride slow with green fluo.